1. Field of the Invention
The present invention relates to a winding core holding mechanism for supporting a winding core on which a thin medium such as paper, film or cloth is wound in a roll, relates to a roll medium holding device having the winding core holding mechanism, and relates to a winding device using those. More specifically, the present invention relates to a winding core holding mechanism suitable for supporting a winding core on which a roll paper output by a large-scale printer is wound, and a winding device using this. Also, the present invention relates to a roll medium holding device suitable for holding a roll paper output by a large-scale printer, and a winding device using this.
2. Description of the Related Art
Normally used as drawing media for large-scale full color printers (of ink jet or electrostatic recording types) are papers, films, or cloths wound on a pipe-like paper tube made of cardboard. One of the means for storing a printed medium is to wind a printed medium 100 on a paper tube 102 by a winding device 101 to store the medium 100 in a roll, as illustrated in FIGS. 26 and 27.
In a device for supplying the medium 100 to a printer 104 (not illustrated) or in the winding device 101, the roll medium 100 is held such that the paper tube 102, on which the medium 100 is wound, is sandwiched by winding core holding members 103 from both sides. Also, the paper tube 102 to be installed in the winding device 101 is the same kind as the paper tube 102 of the medium used in the supply side.
There are two kinds of paper tubes that are normally used according to the hardness and winding characteristics of the medium 100: of 2-inch or 3-inch diameter. In order to hold two kinds of paper tubes 102 in a single winding device 101, the 2-inch core holding member and the 3-inch core holding member are interchangeably used through attachment/detachment thereof. Otherwise, as illustrated in FIG. 28, a 2-inch core holding portion 115 is formed on one side of the winding core holding member 103 and a 3-inch core holding portion 106 is formed on the other.
Since the paper tube 102 is made of cardboard, the inner diameter of the paper tube 102 varies by about 2.5 mm. For example, the inner diameter of a xcfx862 inch paper tube may vary within the range 450 mm to +52.5 mm. For this reason, a holding portion 103a of the winding core holding member 103 is made in a conical shape to hold the paper tube 102 with the tapered surface so that the paper tube is centered and held even if the inner diameter of the tube 102 is not uniform.
Furthermore, the medium 100 is output in sizes of B0, A0 through A2, for example. Therefore, roll media of various widths are on the market to meet these size requirements. To meet with media 100 of different widths, one of the winding core holding members 103 may be configured capable of sliding with respect to a stay in the axial direction of the paper tube 102, i.e., in the width direction W of the medium 100, as illustrated in FIG. 30.
To hold the paper tube 102 using the above, the winding core holding member 103 is slid in the width direction W according to the width of the medium 100 to sandwich the paper tube 102. A knob 105 is turned to secure the winding core holding member to the stay 106 so that the winding core holding member 103 will not become loose and the paper tube 102 will not come off. Although the winding core holding member 103 is secured by a screw in this example, a pin may be used as a position fixing means to secure the winding core holding member 103 to the stay 106.
However, using this winding core holding member 103, the components need to be changed according to the diameter of the paper tube 102 as illustrated in FIG. 28. This results in poor operability due to complicated attaching and detaching operations. Also, a cap, fixture, etc. may be lost during the operation of the attaching/detaching of the components. Moreover, because the winding core holding member 103 uses two different components depending on the size of the paper tube 102, one of the components which is not in use may be lost while the other component is in use.
Furthermore, since the winding core holding member 103 supports the non-uniform inner diameter of the paper tube 102 with the tapered surface of the holding portion 103a, the position on the tapered surface to stop the paper tube 102 varies depending on the size of the inner diameter of the tube 102. Therefore, although the paper tube 102 is centered, the end face 102a thereof in the width direction W cannot be constantly positioned at the same position in the width direction W. For this reason, the center of the winding position of the paper tube 102 is shifted from the center of the winding core of the medium 100 output by the printer 104. If the front end of the medium 100 is set and attached along the width of the paper tube 102 and winding is started under this condition, the medium 100 easily wanders off, making a winding-up difficult. In view of this, a paper tube 102 slightly longer than the width of the medium 100 needs to be used. With this, however, a winding core which is exclusively used for the winding purpose should be used for every medium of different width. This results in complicated storing and managing of the cores. Also, the paper tube 102 that was used in the supply side cannot be recycled. Moreover, the paper tube 102 has ends which stick out of the edges of the roll medium after winding-up.
In addition, when the winding core holding member 103 is positioned and fixed by a rotation of the knob 105 or by a pin, two different sliding and locking/unlocking operations are required for moving/locking or unlocking/moving the winding core holding member 103. This results in poor operability. Particularly, to move the winding core holding member 103 to detach the medium 100 after winding, the heavy wound-up roll medium 100 is handled with a single hand. Thus, he operation becomes troublesome.
If a winding core is used exclusively for a winding purpose, instead of using the recycled paper tube 102, the winding core may be easily attached/detached to the winding device 101 or to the printer 104. With this, however, a winding core needs to be prepared for every medium of different width. This results in complicated storing and maintaining of the components, and also the paper tube 102 that is no longer needed in the supply side will be wasted.
Then, a primary object of the present invention is to provide a winding core holding mechanism which can hold two kinds of winding cores of different sizes without changing components and can position both kinds of winding cores at a predetermined reference position, and a winding device using the core holding mechanism.
Another object of the present invention is to provide a roll medium holding device which can easily attach/detach a winding core such as a paper tube, and a winding device using the roll medium holding device.
To achieve the above objects, the present invention provides a winding core holding mechanism for holding at least one of the end portions of a winding core on which a thin medium such as paper, film, or cloth is wound, comprising a base fixed in the axial direction of the winding core, a larger diameter reference portion, which is capable of axially moving in and out of the base and which abuts to an end face of the winding core, a tapered larger diameter centering portion, which is capable of axially moving in and out of the larger diameter reference portion and which fits into the winding core of larger diameter, a smaller diameter reference portion, which is capable of axially moving in and out of the base and which abuts to an end face of the winding core of smaller diameter, and a tapered smaller diameter centering portion, which is capable of axially moving in and out of the smaller diameter reference portion and which fits into the winding core of smaller diameter. With this invention, to hold the winding core of larger diameter, the larger diameter centering portion centers the winding core while falling into the larger diameter reference portion, and the larger diameter reference portion falls into the base to position the end face at a predetermined reference position with respect to the base; to hold the winding core of smaller diameter, the smaller diameter centering portion centers the winding core while falling into smaller diameter reference portion, and the smaller diameter reference portion, the larger diameter reference portion, and the larger diameter centering portion fall into the base to position the end face at the reference position.
Thus, the winding core of larger diameter is centered by the larger diameter centering portion and is positioned at the reference position by the larger diameter reference portion. The winding core of smaller diameter is centered by the smaller diameter centering portion and is positioned at the reference position by the smaller diameter reference portion. The winding cores of both larger diameter and smaller diameter can be held in this manner without changing the components. This improves operability and eliminates a complicated management of the components.
Also, the reference position for the winding core can be always at the same position regardless of the size of the attached winding core. Therefore, when the winding core holding mechanism is used in a printer or a winding device, the position of the medium output by the printer is easily aligned with the position of the winding core. This prevents the medium from an oblique winding.
Further, each reference portion supports the winding core by the end face, and each centering portion centers the core with the tapered surface thereof. Therefore, even if the inner diameter of the winding core is not uniform, the center of rotation is first centered, and then the winding core end face is always set at the reference position.
The invention further provides a winding device for winding a thin medium such as paper, film, or cloth output by a printer on a winding core, comprising the winding core holding mechanism as described above to hold the winding core.
Therefore, the reference edges of the medium supplied by the printer can be easily aligned with the reference position on the winding side. This prevents the medium from an oblique winding.
To achieve the above objects, the invention also provides a roll medium holding device that has a winding core holding mechanism for holding one end of a winding core of a thin medium such as paper, film, or cloth wound in a roll, a slider portion fixed to the winding core holding mechanism, and a guiding portion for supporting the slider portion to be capable of sliding along the width direction of the medium, comprising a locking means that locks the slider portion from sliding in the direction away from the winding core, and an unlocking means that unlocks the locking means.
To attach the winding core, the slider portion is pushed and slid toward the winding core. As the winding core holding mechanism abuts to the winding core and holds it, the pressing effect on the slider portion is stopped. At that time, the slider portion will not move away from the winding core due to the effect of the locking means; thus, the holding condition of the winding core is maintained. With this, the winding core can be attached by a one-touch operation.
To remove the winding core, the unlocking means is operated to slide the slider portion and the winding core holding mechanism. Thus, the winding core can be removed by an easy operation almost like the one-touch operation.
The invention further provides the roll medium holding device as set forth above, wherein the locking means has wedge-shaped facing planes formed between the slider portion and the guiding portions and a stopper member for locking relative movement between the slider portion and the guiding portions.
Thus, the locking means can be composed of a simple mechanism. Accordingly the cost of the roll medium holding device can be reduced.
The invention still further provides the roll medium holding device as set forth above wherein the operational direction of the unlocking means agrees with the receding direction of the slider portion. Therefore, the operation of the unlocking means and the receding operation of the slider portion can be performed by a one-touch operation. This improves operability.
The invention additionally provides a winding device that winds a thin medium such as paper, film, or cloth output by a printer, comprising the roll medium holding device as described above. With this, the operability is improved for installing an empty winding core in the winding device and for removing the wound-up roll medium from the winding device.